Not sure if this has been posted already, but basically, I would like to see support added for Steam to allow users to install games on different Hard Drives instead of only the one you installed Steam on.

I think it would be a particularly useful feature for both people who first installed Steam without knowing that they would be installing EVERY game they got for Steam on the same Hard Drive (Me).
It would also be helpful for users who have a LOT of games on their account but not enough space on just one drive to fit them all.

With any Non-Steam game, you are able to choose where you want the game to install, it would be nice to have the same freedom with Steam games. Even if it meant you had to install some sort of Steam extension application to the other Drive first (To my knowledge you cannot install Steam on two different drives at once), it would be a nice feature to have.

Just a thought.

I came to the realization the other day that I had just preordered L4D2 and have no room on my Primary Hard Drive to install it. While I do have the space on my secondary Hard drive, I REALLY would prefer not to have to uninstall everything and download/reinstall it on the other drive (I'm pretty sure I could probably copy all of the data files over to the other drive and then install Steam on it to save the download time, but it's still a bit more hassle than I would prefer...).

Tutorial: move single Steam games to other partitions/drives
Technical background
Windows NT (Windows XP, Vista, 2000 and 2003 ARE Windows NT) uses a filesystem called NTFS. It allows creating junctions. A Junction is a folder which is displayed on let's say C:\Source but it's content is in fact at D:\Destination. So the space is used on D: which allows you to have more data on C: than actially possible. And that's exactly what you may want.

Requirements

1. Windows NT (again, WinXP, WinVista and so on ARE WinNT)
2. NTFS-formatted drives (if you still have FAT(32)-formatted partitions, you can use the convert-command to convert your partitions to NTFS, at the cost of readability in Win98/Linux).
3. Some spare time

Execution

1. If you're not using Windows Vista, you'll have to get linkd.exe from the Windows Server 2003 Resource Kit Tools. If you're using Windows Vista, you already have a command called mklink which does the job. I'm going to use linkd-syntax in this tutorial, mklink has almost the same syntax. You only have to add the /j-parameter (junction, remember?) You can access help for both tools with the [tool name] /?-command.
2. Take a look at your folder structure. Where do you want to move the games from and to? In this example, I'll use C:\Steam as the Steam installation directory on a full partition and D:\SteamSpare as the swap space.
3. Open your console. Press Win+R, type cmd and press enter.
4. Let's move a third party game first. Copy the content of C:\Steam\SteamApps\common\Red Orchestra to D:\SteamSpare\Red Orchestra. You have to copy the files because they will be deleted on the original location.
5. Type linkd "C:\Steam\SteamApps\common\Red Orchestra" "D:\SteamSpare\Red Orchestra" in the console.
6. You're done. Red Orchestra files will take space on D: but will be still avaible to Steam in C:\Steam.
7. Moving Valve games is more complicated. linkd can only "mirror" folders. Valve games have their data inside GCF-files. So you can only "mirror" the whole SteamApps-folder or use mklink (Vista only, not tested) to move single files. EDIT: Windows XP has a command called fsutil, it can be used to mirror single files.

I tried the tool out and it works PERFECTLY. I was actually impressed at how well it worked.

Basically what you do is copy the files into a folder on your other hard drive (just like step 4 of the previously posted guide), you then delete the files from the original location (but not the folder they are in, so you keep the directory, but it's empty), then use the Junction Link Magic tool to "create" a link between the files previous location and the new one.

The link in every effect acts as though the files are still in their original location (even viewing them in windows explorer they still appear there) the only ways you can really tell are seeing the difference in hard drive space available now that you don't have the files there, and the other way to tell is use the "scan" function of the tool to detect existing links.

Glad I finally got that resolved, but, again, it would still be nice if Steam just supported multiple drives to begin with.

First off, "ln" is not a windows command. It's "mklink". It's cumbersome because you have to leave Steam and open a command prompt, rather than just type the destination into Steam. Also, there are a lot of people who are unfamiliar or uncomfortable with the command line.

Finally... how is specifying an install location in Steam asking for any more trouble than symlinking your filesystem?

I'm not saying this solution doesn't work, it absolutely does. It would be a smoother user experience, however, to just support different install locations natively in Steam.

I created an account just to reiterate the OP's point. Where's the native multiple hard drive support?

Just built a new rig yesterday. Top of the line with an OCZ Agility 120 GB SSD. This SSD has 100 GB after Windows 7 Pro and other essentials. It set me back a good $370 plus tax and I'd like to do a little gaming on it. Now I'm installing Ghostbusters and if I get Dragon Age: Origins and Aion...that's about half the remaining space of the drive. Not to mention the countless games I've already purchased that I simply can't install if I'd like to use this drive.

I could throw my Steam account on my 300 GB VelociRaptor, but I didn't drop all this cash on an SSD for it to sit there.
This little non-feature is making me contemplate moving back to hard copies when I've been a loyal Steam user for years. Even when the price is higher on Steam.

I think the demand is there and with all the Steam updates we download every four days...why not get the programmers on this? I'm a hardware enthusiast. I like to buy lots of games. It shouldn't be on me to move my Steam folder to my Caviar Black eventually, if I want to keep everything installed. If anything, it's a bandwidth cost to Valve for me to delete and re-install games whenever I want to play something else. Do us both a favor and add NATIVE SUPPORT.

Not like anyone important is going to read this anyway. I suppose a petition is in order?

First off, "ln" is not a windows command. It's "mklink". It's cumbersome because you have to leave Steam and open a command prompt, rather than just type the destination into Steam. Also, there are a lot of people who are unfamiliar or uncomfortable with the command line.

Finally... how is specifying an install location in Steam asking for any more trouble than symlinking your filesystem?

I'm not saying this solution doesn't work, it absolutely does. It would be a smoother user experience, however, to just support different install locations natively in Steam.

The request was to be able to specify multiple locations. You can already specify "a"(n) install location when you install steam.